In vehicle headlights, a wide variety of optical systems are used. These systems use light bulbs, LEDs and lasers as light sources. Standard optical systems frequently include reflectors implemented as direct or indirect reflectors, Fresnel lenses or other lenses and light-guiding lenses in a variety of forms.
Laser light sources can be used to generate a very high luminous flux in comparison to other light sources as a result of their very high luminance. From the perspective of optics and illumination, this property offers numerous advantages in lighting technology. Laser light sources are relevant to lighting technology in cases where the narrow light beam emitted from the laser (e.g. blue) is converted into a wider beam of light (e.g. white) by a converter element (e.g. yellow phosphorus).
However, laser light has the potential to damage the eye or even cause blindness under certain circumstances. This may happen if the converter is damaged in some way.
The established state of the art of technology uses photo diodes to detect damage in the headlight. Headlight damage can only be detected from the total luminous flux over a certain range of wavelengths. One disadvantage of the current state is that there must always be an opaque component, i.e. a filter and sensor, present in the middle of the light image or a select portion of the total luminous intensity distribution must be removed for the purpose of damage detection and is lost as a result.
Another option from the known state of the art of technology involves using scattered light for monitoring, since scattered light is already being lost from the useful light current. The disadvantage of this variation, however, is that the signal-to-noise ratio is relatively large, making the technique relatively imprecise.